The goal of this study is to further our understanding of the mechanisms underlying the vulnerability of the developing rodent brain to epileptic seizures, and to determine whether those mechanisms apply in the primate brain as well. To accomplish those goals, we will: (1) Develop a model of neonatal repetitive seizures in the rabbit. (2) Investigate the role of anoxemia in brain damage from neonatal seizures, by delivering seizures to newborn rabbits paralyzed and ventilated with 50% O2. (3) Study the role of the immature blood-brain barrier in brain glucose depletion during neonatal seizures, and the mechanism by which glucose loads prevent this depletion and protect the brain. (4) To examine the relationship between the effects of seizures on cyclic nucleotide metabolism and their effect on brain growth. (5) Study the effects of seizures on the immature primate brain, including the effects of seizures on brain growth and on glucose transport across the immature blood-brain barrier. We hope our results will suggest measures directed toward the prevention of mental retardation and of epileptic brain damage in the convulsing neonate.